Mathematics questions and answers

Mathematics Questions and Answers

How good are you with figures and formulas? Find out with these Mathematics past questions and answers. This Test is useful for both job aptitude test candidates and students preparing for JAMB, WAEC, NECO or Post UTME.

211.

If sin θ = -  \(\frac{3}{5}\) and θ lies in the third quadrant, find cos θ

A.

\(\frac{4}{5}\)

B.

- \(\frac{5}{4}\)

C.

\(\frac{5}{4}\)

D.

- \(\frac{4}{5}\)

Correct answer is D

Where sin θ = \(\frac{opp}{hyp}\) → \(\frac{-3}{5}\)

opp = -3, hyp = 5

using pythagoras formula 

hyp\(^2\) = adj\(^2\) + opp\(^2\)

adj\(^2\) = hyp\(^2\) - opp\(^2\)

adj\(^2\) = 5\(^2\) - 3\(^2\) → 25 - 9

adj\(^2\) = 16

adj = 4

cos θ = \(\frac{adj}{hyp}\) → \(\frac{4}{5}\)

In third quadrant: cos θ is negative → - \(\frac{4}{5}\)

 

212.

If the mean of 2, 5, (x+1), (x+2), 7 and 9 is 6. Find the median 

A.

5.5

B.

5

C.

6.5

D.

6

Correct answer is C

Firstly; solving for x

6 = \(\frac{2 + 5 + x+1 + x+2 + 7 + 9}{6}\)

cross multiply to have:

6 * 6 = 2 + 5 + x+1 + x+2 + 7 + 9

36 = 2x + 26

36 - 26 = 2x

10 = 2x

x = 5

Median = \(\frac{7+6}{2}\)

→ 6.5

213.

If a fair coin is tossed twice, what is the probability of obtaining at least one head?

A.

0.25

B.

0.75

C.

0.5

D.

0.33

Correct answer is B

No explanation has been provided for this answer.

214.

The shaded portion in the venn diagram above represents?

A.

F - (E n F) - (G n F)

B.

E' n F n G'

C.

E u F u G

D.

F

Correct answer is B

-The shaded/stripped portion in the diagram is set F only.
-This implies that sets E and G though present in the Universal set, are not included in the expression.

-Mathematically; we have E' n F n G'

215.

Evaluate \((101_{two})^3\)

A.

\(111101_{two}\)

B.

\(11111101_{two}\)

C.

\(1111101_{two}\)

D.

\(11001_{two}\)

Correct answer is C

\((101_{two})^3\) = \((5_{ten})^3\)

5\(^3\) = 125

And 125 =  \(1111101_{two}\)